#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>
#define ll long long
using namespace std;
ll a,b,x,y,d,p,q,minn,ans;
bool flag;
void write(ll n){if(n<0){putchar('-');write(-n);return;}if(n>9)write(n/10);putchar(n%10+'0');}
ll read(){ll x=0,f=1;char ch=getchar();while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}while(ch>='0'&&ch<='9'){x=(x<<1)+(x<<3)+(ch^48);ch=getchar();}return x*f;}
void exgcd(ll a, ll b, ll &x, ll &y){
    if(!b){d=a;x=1;y=0;return;}
    exgcd(b,a%b,x,y);
    ll tmp=x;x=y;y=tmp-a/b*y;
}
void solve(){
    x=read();y=read();p=read();q=read();minn=9e18;flag=false;
    exgcd(2*(x+y),p+q,a,b);
    for(ll i=x; i<x+y; i++) for(ll j=p; j<p+q; j++){
        if((j-i)%d!=0) continue;
        flag=true;
        ll k=(j-i)/d,num=a*k;
        num=(num%((p+q)/d)+((p+q)/d))%((p+q)/d);
        minn=min(minn,num*2*(x+y)+i);
    }
    if(!flag) write(-1);
    else write(minn);
    putchar('\n');
}
int main(){
    ll T=read();while(T--)solve();
    return 0;
}